Separator for liquids having different specific gravities



' May 21, 1935. H. A. THOMPSON 7 2,002,253

SEPARATOR FOR LIQUIDS HAVING DIFFERENT SPECIFIC GRAVITIES Filed Feb. 24, 1932 6 Sheets-Sheet l May 21, 1935. H. A. THOMPSON SEPARATOR FOR LIQUIDS HAVING DIFFERENT SPECIFIC GRAVITIES Filed Feb 24, 1932 6 Sheets-Sheet 2 EerZerZ 11% Tiwmpsom Z/Zelg W, Q MrKM' 1 May 21, 1935. H. A. THOMPSON 2,002,253

SEPARATOR FOR LIQUIDS HAVING DIFFERENT SPECIFIC GRAVITIES Filed Feb. 24, 1932 6 Sheets-Sheet 3 May 21, 1935.

H. A. THOMPSON SEPARATOR FOR LIQUIDS HAVING DIFFERENT SPECIFIC GRAVITIES Filed Feb, 24, 1952 6 Sheets-Sheet 4 V lnz''nl'br Erlerl" 11?. T [win 17.7021,

y 21, 1935- H. A, THOMPSON 2,002,253

SEPARA'I'OR FOR LIQUIDS HAVING DIFFERENT SPECIFIC GRAVTTIEJS Filed Feb. 24. 1932 6 Sheets-Sheet 5 May 21, 1935- H. A THOMPSON 2,002,253

SEPARATOR FOR LIQUIDS HAVING DIFFERENT SPECIFIC GRAVITIES Filed Feb. 24, 1952' 6 sheets-sheet 6 F/a ll.

Patented May 21, 1935 PATENTOFFICE sEPARAtroit FOR, LIQUms nAvInG DIF- FEREN'I SPECIFIC. GRAVITIES Herbert Alexander Thompson, Benton,

' Northumberland, England 1 Application February 24, 1932,'Serial No.

. This invention relates to separating devicesor the like for separating liquids of different specific gravities from a mixture of such liquids, "the separator being of the type which consists of a casing having arranged in its interior a number of quiescence chambers throughwhich ,the liquid mixture is caused to flow for the purpose of en: abling the differencerin. the specific gravity of the liquids forming the mixture to become effective in separating the liquids, the rate of fiow'of the liquid mixture through the apparatus being made as low as possible for this purpose.

Separators of this type have been employed for removing any oil leakage from thecondensed Water drawn from the steam heatersof oil-burning installations to enable such condensate to be so cleansed that it may be returned to the steam boilersdirect for feed-water. In the type of construction above referred to the divisionsbetween the chambers are usually so arranged that the flow ofmixture to be separated into its "component liquids is made to take an up and downor other tortuous course. I V i In order to allow the separation to be ascomplete as possible it is usual to arrange that the liquid mixture has a considerable distance to travel within the confines of the apparatus and for this reason the liquid mixture leaving one quiescence chamber, where some of the component liquids separate out, is usually brought into the next quiescence chamber at the ,bot-

tom thereof so that the lighter component of the mixture has to rise through the whole of the chamber. Besides the risk of contaminating the heavier component of the mixture which may have separated out at. the bottom of thesecond quiescence chamber the whole of the liquid in'this chamber is agitated by the entry ofthemixture at the bottom thereof and the necessary degree of stillness is not obtained. .These disadvantages are overcome, in the construction according to the present invention by arranging that the. entry of the mixture into any quiescence chamber occurs as near as possible to thepoint, where one of the separated liquids is collected. and alsoat a level at which the horizontal cross-sectional area of." liquid is greatest so that theentering liquid is "enabled to distribute itself over "the largest possible surface and thereby attain maximum quiescence as soon as possible;

In order to determine the most eflicient and compact form forsuch apparatus, I have carried out a number-of experiments with a known type -ofapparatus of my own design which is-used for removing oil irom' condensed, water irom the In Great Britain January 16 Claims, ((1210-43) steamheaters of oil burningiinstallations as above referred to; This ;apparatus usually consisted of a rectangular tank having. arranged internally thereof a series of divisions or baiiles so arranged thatthe condensate flowed for example, over the top of the first baflie, under the second, over the top of the third baiiie and so on so that by this means the oil, being of lighter specific gravity than the water, tended to float to the surface of each chamber formed by the baffles from which it was collected. By using a suitable number of divisions the'wholeof the oil was more or less removed by this means; but to secure complete removal of the oil I usually arranged that the last chamber beforethe outlet was provided with a perforated plate bottom and loose lid between which was placed a filter bed of broken coke, rubble-sponge or filter cloths which effectively removes the last traces of oil. H

The main objection to the use of such apparatus is thatbfor a given output the separator tends to become very unwieldy in length owing to the number of chambers employed to obtain high eiiiciency and, as the result of my experiments to determine the best method of providing a smaller and more compact apparatus, I found thatit was advantageous tohave at the inlet a swirl chamber or compacting chamber in which the mixture of liquids to be separated, such as, for example, oil

and water, was gi'ven a swirling action and by the turbulence caused the particles of oil coalesced into large masses which more readily flowed to the top of the chamber than did tiny globules merely discharged directly into a quiescence chamber. 7 Having united the globules of oil into larger masses I then found that it was advantageous to effect the removal of these large masses as quick- .ly as possibleirom the main fiowland I therefore arranged a collecting chamber or oil dome adjacent to the line of flow from the swirl chamber but oiT thedirect line of flow of the mixture, so

that once these masses of oil entered the dome they were in a, chamber which was free from any disturbances caused by the main flow currents. Thus in the case of amixture of oil and water ,main flow, and on observing these particles I found thatthey were'really globules of water encased in an envelope of oil and to .removethese from the main flow I arranged that-the mixture ber of relatively large capacity in relation to the flow volume to enable these particles, which were almost of the same specific gravity as that of the mixture, to assert their rising power which would carry them towards the oil dome before they could be swept into the next quiescence chamber by the flow current. Furthermore, I'found that whenever these oil globules touched an oily sur face they tended to adhere thereto and in view of this feature and to assist the globues in rising I designed the cross-section of the quiescence chambers in such a manner that the side walls thereof were inclined inwardly'and upwardly towards the top surface and the oil dome. Also, as

the main flow of liquid -mixture was at the level of the inlet I observed that the horizontal crosssectional area of water should be greatest at that level to obtain the highest degree of quiescence. For these reasons, namely, to direct the separated oil towards the oil dome and to provide the highest degree of quiescence at the inlet level I prefer to make the quiescence chambers of ovate crosssection as this form of construction gives sufficient depth of liquid without having an equal volume of liquid at the top to that'at the bottom as the oil content is,always at its lowest percentage at the bottom of the chamber. The swirl chamber is also preferably made of ovate crosssection as it enables curved vanes and the like for obtaining turbulence to be dispensed with, for by directing the fiow downwards at its entry into the swirl chamber the stream is caused to break up into two ascending currents which are turned inwards at the top by the curved walls and so start a gyratory movement Within the chamber, the velocity of this movement being sufficient to impact the smaller particles of oil into larger masses as desired. The provision of these three features, namely, the swirl chamber, an ovate cross-section of quiescence chamber and the provision of an oil dome ofi the line of flow of liquid, enables the rate of fiow through the apparatus to be increased ascompared with apparatus of the previously known type of an equal size and capacity.

By carrying out further tests for increasing the rate of flow, I found that whilst in the first stages the, main masses of oil were eifectively removed there was now present at the higher rates of flow the danger of oilenveloped particles being discharged through the outlet into the next quiescence chamber, but, instead of increasing the length of the apparatus by adding further quiescence chambers to the outlet end, I find that the ovate section adopted in the case of the initial quiescence chamber enables the additional quiescence chambers to be arranged ona return flow principle by enclosing the first chamber in a sec- 0nd or outer chamber also of ovate shape.

The apparatus hereinafter described in detail for the separation of oil and water is therefore constructed in the manner indicated above, namely, with a first-stage or inner quiescence chamber of ovate cross-section surrounded by an outer casing or shell, also of ovate cross-section and forming further quiescence chambers, the whole being surmounted by an oil dome from which the separated oil is drawn oif. The mixture to be separated is led first into a swirl chamber at the inlet end of the apparatus and is then passed through successive quiescence chambers from which the oil rises to the oil dome while the separated water is drawn ofi from the last quiescence chamber.

, stream should enter a first stage quiescence cham- By arranging the quiescence chambers one inside the other the inner shell and interior parts, being exposed to the same pressure on each side as they are merely immersed in the liquid mixture, can be made of the lightest possible structure consistent with practical manufacture and a considerable saving in the cost of manufacture can be effected as only the outer shell and main oil dome need be made strong enough to stand the working-pressure.

Atthe bottom of the inner or first-stage quiescence chamber and at a point farthest from the inlet, I arrange an outlet passage communicating with the space enclosed between the outer and inner shells and forming the second and later stages of quiescence chambers, and in addition I also place a flow-direction plate below this outlet opening, to impart an upward motion to the flow in the second chamber.

This direction plate directs the flow to the widest area of the outer chamber and the narrowing spaces between the upper portions of the two shells form oil collection spaces or pockets which are also clear of the main currents and by which the oil is directed towards the oil dome. These oil-spaces are connected internally to the oil-dome of the apparatus by so forming the top side of the inner shell adjacent to the main oildome, that it forms communicating passages for this purpose. Instead of connecting the oil-collection pockets with the oil dome in this manner they may be connected thereto by internal or external pipes. I

By adding stepped flow plates and divisions in the outer chamber a further series of quiescencechambers within the length of the apparatus are obtained.

As the spaces within the main oil-dome, the inner and outer chambers are all in communication they are in'static balance as regards the water-flow pressure, and any oil separated in the outer or later-stage quiescence chambers can fiow freely up to the main oil-dome by reason of its lower specific gravity compared with that of the main-flow water. i

The main fiow of mixture to be separated can pass freely whilst oil is collecting in the oildome, and the latter may be emptied when full by opening a suitable discharge valve to enable the oil to be led away by a pipe to a collection tank or other suitable place. The oil discharge valve may be operated by hand, or the oil can be drawn off automatically as soon as a predetermined quantity of oil has collected in the oil dome by means of a standard float mechanism operating the valve directly to open or close the latter when the oil reaches a predetermined high or low level in the dome, the float being suitably balanced so that it will sink in oil but float in water or the heavier of the two liquids being dealt with.

As the mechanical effort due to the flotation difference between the specific gravities of the liquids dealt with is often very small, however, I prefer to use such a balanced fioat only as an indirect control for opening and closing the oil valve.

For this purpose I arrange a suitable balanced float within the oil-dome, connected by levers to a shaft, housed in suitable bearings, one end of the shaft passing out through the wall of the dome to the exterior, being kept water-tight by a gland and stufling box. To the outer end of this shaft is rigidly fixed another lever to which is attached a movable balance weight for adjusting purposes. As the float rises or falls within the domasothe external lever moves correspond ingly'outside and this lever is employed'to operate an easily moved pistonevalvecontrolling the main piston-valve or slide-valve of a cylinder andpiston, the piston rod of the latter. being suitably connected to the spindle of the; oil-discharge valve. f

.Tlhespindle of the first gmentionedpiston-valve has adjustable triggers attached to it at a suitable distance (apart, so that the external floatoperated lever is allowed lostmotion between these triggers'and the valve spindle is only moved towards the end of either the up or down stroke of the lever when it engages oneor the other of the triggers.

' "This arrangement enables the discharge valve to remainclosed whilst the dome is filling with oil to a predetermined level, and although the float will sinkas the, oil content increases, the piston valve will not be operated until theexter nal lever reached the valve trigger .near the end of its upward stroke and carries it to the limit of its stroke thereby causing the main engine slide valve tobe thrown over and so admit fluid under pressure to one side" of the piston which moves in the cylinder and opens the oil valve.

The oil-discharge valve will then remain open until the oil has been discharged from the dome to a given level and, as'the oil is discharged, water will rise in the dome to take the place of the dischargedoil, causing the float to rise 7 and the external arm to fall and; when the arm meets the lower piston-valve trigger near the end of its stroke it will carry it downwards with it and so reverse the engine slide valve, whereon fluid under pressure will. be admitted to the op posite side of the piston so that the latter moves to closeithe oil valve. During these operations the opposite side of the piston to that on which pressure is appliedis of course open to exhaust.

Instead of using pressure alternately on each sideoi the piston for opening and closing the oildischa rge valve, the latter may be maintained closed by a loaded spring attachment and opened against the action of the spring by means of the mechanism just described but in which fluid under pressure isadmittedto one side' of the piston only, the valve being closed by the spring when the pressure is released. With this ar- 1 rangement the opposite side of the piston to that on which pressure is applied is continually open to exhaust but the working side is alternatelyopen to pressure or exhaust depending on position of the extern'al'lever which operates the cylinder slide-valve. A If the separator is working under pressure other than atmospheric pressure, a pipe may be led from, say, the lower chamber'to the operating cylinder and the water or other fluid utilized to operate the piston, but if desired steam, air or other fluid under pressure from an external source may be employed for this purpose.

Alternatively the external lever may be used in any suitable manner to control electrical switch-gear of any of 'thewell-known trip-gear types or it may be employed to throw over alternately from one side to the other the well known type, of mercury-tube contact switch which may control directly, or through relay-switches, suitable electrically operated mechanism for open-. ing the oil-discharge valve, or suitable electrical alarms, signal-lamps, sirens pr whistlesor the like may be operated in thismanneror directly by the external float-arm; particularly in cases where the control of the oil-valve is by hand;

or electrical heating-elements in any suitable position or positions within any of the chambers,- preferably along the crown of the top inner chamher and around the internal circumference of the oil-dome clear of the float gear, if this is fitted. With very viscous oils the heating of the dome contents would prevent sticky masses of oil clinging to the float mechanism and upsetting the adjusted balance of the gear. Filtering chambers filled with coke, sponges, filter-cloths and the like may be fitted in cases wherethe apparatus is used in processes where not the slightest trace of the oil or other contaminating fluid must be allowed to pass out of the separator, or, if desired, the apparatus may be connected at its outlet to ordinary standard filters sold for this purpose. i Since oilsare'fnow in use which are heavier than water the apparatus is so arranged that it can be used in an inverted position, the oil-dome then becoming an oil-well or sumpfor this heaviertype. of oil, the separated oil being'dischargcd in 'a' similar manner to that previously described. ,On this account the apparatus may be used in pairs, one device being inverted to remove heavy oil from the mixture while the other removes a second oil of a lighter nature so that an oil-free dischargis thus obtained.

Furthermoraby the use of an inverted apparatus it is possible to' deal with, for example,

petrolcontaminated with water, a small form ofthe apparatus being inserted in the petrolsupply pipe leading'to the carburettor of a petrolengine, with the result that water, or even solid matter, is; precipitated into the inverted dome, which maybe in theform of a glass cylinder suitablyheld in place by a removable cover which is provided with "a drain-cock or valve to draw bemanufa'ctured from pressings or stampings, welded, brazed or soldered together, so that a, sealed vessel is formed without removable covers or joints for access to the interior.

Instead of constructing the chambers of ovate cross-section, any other suitable form may be employed, such as circular, rectangular,triangular and the like, as although these are not so eificient, they will yet form an apparatus constructed on the lines previously described.

constructional forms of apparatus according to the invention are illustrated in the. accompanying drawings, wherein:-

Fig. 1 shews asectional View in side elevation of the apparatus, shewing the oil-dome, swirlchamber, and the various quiescence chambers and internal parts.

Fig. 2 is a part-sectional plan view of this device with the oil dome cover removed, the section being taken on line 22 of Fig. 1.

Fig. 3 is an external end view of Fig. 1 showing the arrangement of inlet and outlet pipes and valves. p

v Fig. 4 is a part sectional end elevation of 1.

Fig. 5 is a sectional side view of a modified are rangement of device. I s m Fig. 6 is a part-sectional end View of Fig. 5.

Figs. 7 and 8 are detail views of the oil-discharge valve operating gear, showing modifications.

And Figs. 9, 10, 11 and 12 are sectional and outside end elevations, a part-sectional side elevation, and an underside plan, respectively, of an inverted separator arrangement suitable for insertion in the petrol supply pipe of petroleugmes.

Referring first to Figs. 1 to 4 the apparatus consists of a main or outer shell I of ovate crosssection inside which is arranged an inner shell 2, also of ;ovate cross-section, and which extends from end to end of the outer shell I. An oil dome 3 is secured on the top of the outer shell 1, preferably in a mid-position as shewn. The oil-dome 3 is fitted with a removable cover 4 having an oil-discharg e branch 5 to which a suitable oil discharge valve 6 is fitted, this valve being arranged to be operated by hand or automatically by means such as the mechanism to be later described. The shell I is provided with end plates or covers I, l which may be fixed or removable as desired and the end plate 7 is provided with an inlet opening 8, situated within the confines of the inner shell 2, and an outlet opening 9 is provided leading from the space below the inner shell 2. Over the inlet opening 8 is fixed a flare-mouthed direction plate lil by which the fiow of entering liquid is directed downward- 1y into the converging space of a swirl-chamber l 1 formed at the inlet end of shell 2 by arranging a suitable division plate l2 across the width of shell 2. The top edge of this plate 52 is provided with a lip it to act as a flow-direction plate or guide.

The quiescence chamber [4 formed by' the remainder of the inner shell 2 is in communication with the lower space by means of a passage Win the bottom of shell 2, such passage being preferably formed by shell 2 being bent into flanges it at this point. A vertical or inclined flow-directing plate 41 is fitted to inner shell 2 at a suitable position as shewn adjacent the passages l5 and below these passages is fitted a curved baffle plate l8 which is supported, and connected to shell 2, by plates l9.

A suitable number of division plates 28 are arranged as shown in the space betweenthe outer and inner shells l and 2 to divide this space into a number of additional quiescence chambers 2!, the plates 26 also acting as supports or stiffeners for the inner shell 2. These plates 26 are not carried right to the top of the space between the two shells in order that each chamber 2! may be in communication with its neighbour by reason of the gaps or passages 22 so formed. The spaces bounded by the outer and inner shells i and 2, and the plates 20, or these plates and the end plates 1, l form upwardly directed passages 2 la.

Flow-directing plates '23 arranged alternately with plates 2!] are fitted at the bottom of the outer shell to act as diverting plates to give the main flow an upward motion and these also act as stiffeners or ties for the shell I.

In Figs. 1 and 4 the inner shell 2 is shewn secured along its top side to the outer shell i for its full length except where the oil dome 3 is fitted to the outer shell. At this point the sides of shell 2 are carried upwards into dome 3 by means of flanges 24 or the like, so that a passage or space 25 is formed on each side between. the flanges 2t and the walls of dome 3 and these passages 25 thus form continuations of the passages 22 previously referred to and so put the latter in communication with the interior of dome 3. The flanges 24, by being carried into the dome, prevent eddy disturbances from the main flow in shell 2 interfering with the quiet rising of the separated oil from passages 22 into oil-dome 3.

Fig. 3 shows in dotted outline a suitable arrangement of connecting pipes and valves for connecting the apparatus into the main' flow pipe system 26.. Into the main pipe line 25 is inserted a T-piece 21, a shut-off valve 28, and a second T-piece 2s. The T-piece 2'! is connected to inlet valve 30 which is joined by pipe 3| and bend 32 to the inlet 8 of separator, while, by means of a bend 33, a pipe 34 and an outlet Valve 35, the flow is led from outlet 9 back to the main pipe line. The valve 28 is insertedin the pipe line 26 to enable the flow to pass straight through the pipe 26, when this valve is opened and the inlet and outlet valves 30 and 35 are closed, so as to shut the separator off for cleaning or repairs without stopping the main flow discharge in case of need. If necessary a relief valve (not shown) may be provided in the pipes leading to the apparatus or in the device itself to prevent dangerous rise of pressure in the apparatus when starting it in operation.

Neglecting for a moment the automatic operation of the oil-discharge valve 6, the operation of the apparatus in actual use will now be described and, although the apparatus is intended for use with any mixture of liquids of different specific gravities, it will be described for the sake of clarity,- as dealing with water contaminated with oil-fuel or other light oil.

On first starting the apparatus, it is filled by suitable means to the top of the oil-dome 3 with a supply of clean water, to prevent all its interior surfaces becoming coated with oil deposits. After this the valves 39 and 35 are opened and the valve 2!! closed, thereby permitting the oil contaminated flow to enter inlet 8 where it is diverted downward by director plate ii! to the bottom of swirl chamber H where it is broken up into two streams which flow outwards to the walls of shell 2 which enclose the chamber l l, the division into two streams being assisted, if desired, by deflector 36 placed at the bottom of swirl chamber l I. As the walls of shell 2 converge at the top they direct the two streams into a circular path which starts a gyratory movement at each side. The two streams meet at the centre of swirl chamber ll with the result that the oil particles are pounded together and so compacted that they coalesce and form large masses, which readily remove themselves from the disturbed area, by rising to the surface of the swirl chamber l I where they pass out through the opening l3a arranged between the top of lip l3 of the division plate 92 and the top of shell 2.

These main masses of oil are thrust upwards against the top surface of chamber l4 and advance along same until they reach the opening 2441 between the two flanges 24, where they pass up into the oil-dome 3, and are so taken as soon as possible out of the path of the main fiow. which now proceeds along the line of the top surface of shell 2 through the quiescence chamber M. t will be evident that the primarily separated mixture is introduced by way of the passage 53a at the highest possible level in chamber M, so as to have beneath it a mass of quiescent water. On this account any small particles which have remained uncoalesced, such as oilenveloped water globules, are diffused forward along thistop level at greatly reduced speed, as

' the lower quiescence chambers.

the; volume of space Mismany times the. equivalent of inlet 8. Oily particles will therefore continue to rise to the surface, where, by coming into contact with the converging sidesof shell 2, they will tend to adhere and in'due course creep up the walls in united streams and so also arrive in oildome 3, by way of passage 24a. Towards the end of chamberl4 the flow passes over the baflle plate ll, which causes the flow stream to ascend and so bring any submerged oil particles to the top before the main flow passes down into The main flow now passes through passages l5 and in its clescent the flow stream is diverted. in an upward direction by bafiie 18 on reaching the lower chamber, so that any oil particles which may have been carried along are projected onto the inwardly inclined surface of the underside of shell 2 and these particles, along with others which continue to rise out of the flow, ascendiinto the passages 2 la between thev outer and inner shells l and 2. These passages or spaces Zla are out of the path of the flow stream and so allow any separated oil to flow upwards and pass by the passages 22 and 25 into the oil dome. The whole of thechambers being in hydrostatic equilibrium, ensures the transference of oilf rom these lower spaces 2 land 21a to the oil dome 3 by rea-. son of the difference in specific gravities of the oil'and water. j H l The flow stream continues oniand now meets the first director, baffle 23, which, being either vertical or inclined, again imparts an upward motion to the flow, which gives any remaining particles of oil assistance to reach the second set of spaces or passages 21a, these being situated between the two division plates 20. This further body of trapped oil passes to the oil, dome 3 in a similar manner to that last described. The flow stream now meets the second director baffle 23 with a similar result and this process is repeated according to the number of baffles 23 and divisions 2B fitted. i i The cleansed flow stream apparatus by the outlet 9, andis led by bend 33 and pipe 3% backto the main pipe line 25 and so to its ultimate destination. It will be evident that, as'the main flow proceeds, the oil dome 3 will become full of oil, and to empty this a discharge valve 6 may be opened by hand, the pressure within the apparatus causing the oil to flow out, when it may be taken by a pipe to a suitable destination. Suitable testcocks or gauge-glasses (not shown) maybe fitted to the oil-dome tto ascertain the high and low levels and so enable the operator. to tell when to open or close the valve 5. a If the oil dome 3 requires to be frequently emptied, it is desirable to employ an automatic device to operate the valve 6 and one construction of device for this purpose is illustrated in Figs. 1. to 4. Within the oil dome 3 is arranged a float 31 of suitable design, preferably arranged as shown in Figs. 1,2 and 4, where it is shewn connected to twin parallel arms or levers Y38 and 38a, which maintain the float in a' horizontal position at all levels, the. levers being rigidly coupled to shafts 39 and 3 55a which are carried in sockets or bearings it of suitable design. One end of shaft 39 is extended through the wall of dome 3 to the exterior, leakage being prevented by suitable means, such as a gland and stufling-box 4|, and to the outer end of shaft 39 is rigidly attached a lever arm 42 to which is movably aflixed a balance weight 43. The float 31 is designed to finally leaves the float in water and submerge in oil and the balance weight 43 enables exterior. adjustments to be made if necessary.

As the flotation eifort of the float may not be sufficient for the operation of large valves directl prefer to employ the float to operate only a small piston-type control Valve, such as is commonly used to govern the working movements of the slide-valves of engine cylinders. This piston type control valve, the operating cylinder and its slide valve are indicated generally by reference numerals 44 and 45 as these may be of any well known type'and their construction does not form part of the present invention. The piston-rod #55, is, however, modified at its outer end by fitting a spring-coupling and. shock absorber consisting of a casing 41 which is provided with a cover nut 48 and contains a spiral spring 49 of suitable strength. The oil-discharge valve 6 may be of any standard make or design, but modified by omitting the usual screw-thread on its valve spindle and employing a plain spindle 50 which is free to slide up and down through the stufflng box and gland of the valve, and attached to. the outer end of the valve spindle 5B, or formed there.- on, is a collar 5! which is arranged to fit within the casings! of the coupling so that the spring 69 keeps it firmly in place against the inner face of nut 48 when the latter is screwed on to the casing 41. The oil discharge valve 6 is thus adjustably coupled tothe piston of the operating cylinder, the spring, 49 allowing for any difference of travelbetween the piston of the operating gear and valve 6 when wear occurs in the valve seating. The slide rod 52 of the piston valve 44 is extended and fitted with adjustable operating triggers 53 and 54 ata suitable distance apart to enable them to be engaged by the lever 42 near the limits of its travel to throw over the piston valve 44.

The operation of this mechanism is as follows:

As shewn in Fig. 1, the float is in its highest position, which means that oil-discharge from dome 3 has just ceased, through the valve 6 being closed by the operating cylinder 45. V

Separated oil will again begin to collect in dome 3 and as it accumulates it will displace the equivalent water content, and the float 31 will follow the water level down since it is not designed to heat in'oil, Consequently the exterior lever 42 will rise untilit reaches the trigger 54 and as the lever 42 continues to rise it will lift trigger 54 and spindle 52 and raise the piston valve which causes the mainslide-valve of the cylinder to be reversed so that pressure is admitted to the top side of the cylinder, whilst the lower side isopened .carrying float 31 upwards so that lever 42 moves downwards until it meets the lower trigger 53 which is then pushed downwardly as the float continues to rise, with the result that the piston- Valve reverses the slide valve again, pressure is admitted to the lower side of the piston in cylinder 45 while the top side thereof is opened to exhaust, so that the piston rises and so closes valve 6. This sequence of operations is then repeated each time a predetermined amount of oil has collected in the oil dome 3.

.The oil-discharge valve-opening mechanism may be operated by fluid under pressure supplied from any suitable external source, but when the separator is working under pressure other than atmospheric the mechanism may be actuated by the fluid in the separator itself by means of a pipe 55 extending from a cook 56, fitted say, near the bottom of outer shell I.

A modified form of the apparatus shown in Figs. 1 to 4 is illustrated in Figs. 5 and 6. The construction in this case is in general the same as that of Fig. 1, but instead of the outlet 9 being placed in the lower part of plate I special internal outlet flow passages 51, are arranged at each side, between shells I and 2, at the end adjacent plate '5 these passages meeting as one continuous passage at the top of shell I, in which is arranged the outlet 9, to which is connected at suitable adapter 53, here shewn as a tapering cone, by which the outlet is connected to the flow outlet pipe 34, or if desired, the pipe 34 may be attached direct to outlet 9. This arrangement ensures that the apparatus, once filled, remains so, and prevents the oil level falling to the lower spaces should the valve 35 have been left open when the apparatus has been stopped. The arrangement of overhead pipes in Fig. 3 also achieves this purpose, but in a more cumbersome manner.

. slope where it is attached to shell I.

a In this construction, also, the top of shell I is shown as being sloped up towards the oil dome 3, only the lower part of which is shown, in order toassist the oil in its upward passage to the oil dome and inner shell 2 also follows this same Filter beds 59 and 60 are also shown as fitted at the fiow outlet end of chamber I l and between the two quiescence chambers 2|, these filter beds consistingof the usual bed of coke-gravel, filtercloths, sponges or the like supported by any suitable means such as the perforatedplates 6| and one or more of these filter beds may be fitted as desired.

Access or inspection doors 62, are shown fitted to .the end plate I and'tothe outer shell I and may be fitted in any suitable position which will give convenient access to the'interior of the apparatus, such as for changing the filter beds from time to time.

Figs. 7 and 8 show modified constructions of the oil-discharge valve operating gear, in which the valve is arranged to be closed by spring action but opened by power operated means.

In Fig. 7 the cylinder 45 is attached to the body of the valve 6 by pillars 63 or the like, but the piston-rod B6 is extended downwards through a gland 64 in the lower end of the cylinder and to it is attached a cross member S5 which is capable of sliding on guides 65 rigidly attached to cylinder 45 and at their lower end to a member 61, suitably designed to support a helical spring 68 which is secured between the members 65 and 67 and is'designed to give a pressure load, which will thrust member 65 and piston-rod it; upwards and so close valve 6, whenever the top side of the piston 68 is open to Xhaust. The cylinder space below the piston has a port opening 19, which is always open to exhaust but never to pressure. The cylinder space above piston 69, has a port opening 7 I which is alternatively open to pressure or exhaust, according to the position of the slidevalve 12, which in this case, is attached directly to the rod 52 carrying the triggers 53 and 5 3 which are actuated by the movement of the external float-lever 42.

As shewn in Fig. 7, the valve 6 is shut, as the spindle 52 has previously been moved by lever 42 to put valve I2 in a position which connects port II with the exhaust port so that the top of piston 69 is relieved of pressure thereby allowing spring 68 to close valve 6. As dome 3 fills, lever 42 will rise and in due course engage with trigger 54 and carry it to the position shown in dotted outline above it, and so pull the slide-valve E2 to the position in which exhaust connection is cut off from port II and fluid under pressure is admitted thereto instead. Piston 69 is therefore pushed downwards against the action of spring 58 and so opens valve 6 to allow oil to be discharged. As the dome 3 empties, lever 42 falls and moves valve I2 so that pressure is released from the top of piston 69 and. spring 68 immediately closes valve 6. These operations continue as the dome 3 alternately fills and is emptied. This arrangement provides a definite means of ensuring that the valve 6 remains closed when ever power is definitely out 01? from the cylinder 45 or when the separator is not in use.

Fig. 8 shows an arrangement somewhat similar to the arrangement of Fig. 7, but in which the cylinder 45 is placed alongside the valve 6 and smallspiral springs I3, arranged round the guides 66 are used instead .of the single spring as in Fig. 7. Whilst the cycles of operation for this mechanism are similar to that shown in Fig. '7, in this case the power from piston 69 for opening the valve 6 is transmitted by a lever or twin levers I4 pivoted at "E5 in a bearing carried on a bracket or arm I6, the lever or levers "M being connected to the piston rod 46 and member 65 by links 11, I8 respectively.

Figs. 9 to 12 illustrate a smaller construction of separator designed to deal with a main flow of a lighter fluid than the contaminating one to be'separated, such as petrol and water, respectively, the separator according to the present invention being so designed that it only requires to be inverted and used in the inverted position, to enable the heavier liquid to be separated and drained oft, whilst allowingthe main flow of lighter liquid to continue.

The construction'ofv this latter type of separator, which is suitable for insertion in the feed-pipe to the "carburettor of a petrol engine, is in general, the same as the construction described with reference to Fig. 1 and similar references have therefore been used for similar parts. In this construction, however, the shells I and 2, are cut longitudinally to form top and bottom halvesand are secured together in their working condition by flanges i9 and bolts or screws 80. The oil flow directing flanges indicated by reference 26 in Figs. 1, 2, 4 and 5, are here shown in an alternative form, in which they are made as a tubular extension 24 of shell 2. In this construction also, particularly in the case of petrol separation, the deflector I8 is omitted, as the heavy impacting of petrol is not so important, as it coalesces freely, and, if desired, an additional port I31) may be added in the division plate I2.

In this construction also the dome 3, or, in this case, a sump, consists of a glass cylinder 8! in order to permit of visible observation of the collection of water in the dome or sump 3.

The glass cylinder 85 is secured in place by a cover 82, which is attached to shell I by screwed pillars 83 provided with wing-nuts 841 or the like, the cylinder 8I fitting into annular recesses 85 in the cover 82 and easing I and provided with packing or jointing rings 86. A drain cock 8? is fitted in the cover 82 for draining off accu-o mulated water from the chamber. Instead of the hand operated cock. ill, a float and needle valve, of the type used in petrol carburettors', could be fitted for the purpose of automatically discharging the accumulated water, the float, of course, being arranged to sink in petrol and float in water, and so raise the needle valve and open water has collected.

To reduce manufacturing costs as much as possible, the modified design for petrol separation could be made up from stampings or pressings, welded, brazed, or soldered together without any flanges or other means-for giving access to the interior, since, in the absence of internal mechanical paltsfit may be unnecessary to give the user any such means of access.

In'addition the use of glass for constructing the cylinder 8! may be avoided and this cylinder 8| made of any suitable metal or other material as in the other constructions. V

The construction shown in Figs. 9, 10, 11 and 12, is provided with suitable brackets or feet 88 tor securing the apparatus in any required position, while, in the previously described constructions, suitable chairs or seatings-BQ for supporting and securing the separator in its working position are indicated in dotted lines, but alternative supports of any suitable design may be em ployed to suit the installation-of the apparatus in each individual case as found necessary. Figs. 1 to 6 shew a construction of separator made from steel plates and standard angle bar sections and the like, welded or riveted together,

but if desired the construction may be built up from castings of any suitable material, bolted, riveted or welded together, or byemployinga combination of plates and such castings and the like.

What I claim as my invention and desire to secure by Letters Patent is: i 1. Apparatus for the separation of liquids of different specific gravities comprising an outer shell of ovate form in vertical cross section with its sides converging downwardly, a smaller innerv shell also of ovate form inivertical cross-section similarly arranged inside the outer shell at the top thereof and constituting a first-stage quiescence chamber, a collecting dome or chamber, for the liquid or lower specific gravity, securedt-o the top side of said oute shell and centrally thereof, an opening in said inner shell beneath the collecting dome by which the inner shell isin communication therewith, aninlet opening at one end of said inner shell, a vertical baffle plate adjacent the inlet and dividing off part of the inner shell to form a swirl chamber, an-opening in the bottom of the inner shell, at the Opposite end to the inlet, by which the inner shell is in com: munication with the outer shell, division plates extending between the inner and outer shells and dividing the space therebetween into a number of lower quiescence chambers communicating with the collecting dome, an outlet opening at the bottom of said outer shell, and for drawing oil the lighter separated liquid from the ccllecting dome.

2. Apparatus for the separation of liquids of different specific gravities, according to claim 1, characterized in that a fiare-mouthed direction plate is provided over the inlet opening to direct the flow downwardly on to a defiector so as to set up a swirling motion in the liquid;

3. Apparatus'for the separation of liquids of different specific gravities comprising an outer shell of ovate form in vertical cross-section with its sides converging downwardly, a smaller inner shell also of ovate form in vertical cross-section similarly arranged inside the outer shell at the top thereof and constituting a first-stage quiescence chamber, a collecting dome or chamber, for the liquid of lower specific gravity, secured to the top side of said outer shell and centrally thereof, an opening in said inner shell beneath the collecting dome by which the inner shell is in communication therewith, an inlet opening at one end of said inner shell, a vertical bafile plate adjacent the inlet and dividing off part of the inner shell to form a swirl chamber, an opening in the bottom of the inner shell, at the opposite end to the inlet, by which the inner shell is in communication with the outer shell, baiile plates on both sides of said opening to deflect the flow in an upward direction before and after its passage through said opening, division plates extending between the inner and outer shells and dividing the space therebetween into a number of lower quiescence chambers communicating with the collecting dome, baflle plates in said chambers to deflect the flow upwardly, an outlet opening at the bottom of said outer shell, and means for drawing ofi the lighter separated liquid from the collecting dome.

4. Apparatus for the separation of liquids of differentspecific gravities comprising an outer shell of ovate form in vertical cross-section with itssides converging downwardly, a smaller inner shell also of ovate form in vertical cross-section similarly arranged inside the outer shell at the top an opening in said inner shell beneath the colbetween the inner and outer shells and dividing the space therebetween into a number of lower quiescence chambers communicating with the collecting dome, an outlet opening at the bottom of said outer shell, and means for drawing off the lighter separated liquid from the collecting dome.

5. Apparatus forthe separation of liquids of different specific gravities comprising an outer shell of ovate form in vertical cross-section with its sides converging downwardly, a smaller inner shell also of ovate form in vertical cross-section similarly arranged inside the outer shell at the top thereof and constituting a first-stage quiescence chamber, a collecting dome or chamber, for the liquid of lower specific gravity, secured to the top side of said outer shell and centrally thereof an opening in said inner shell beneath the collecting dome by which the inner shell is in communication therewith, a baille around said opening to assist in directing the lighter liquid into the collecting dome and to prevent eddy cent the-inlet and dividing off part of the inner shell to form a swirl chamber, an opening in the bottom of the inner shell, at the opposite end to the inlet, by which the inner shell is in communication with the outershell, division plates extending between the inner and outer shells and dividing the space therebetween into a number of lower quiescence chambers communicating with the collecting dome, an outlet opening at the bottom of said outer shell, and means for drawing on the lighter separated liquid from the collecting dome.

6. Apparatus for the separation of liquids of different specific gravities comprising an outer shell of ovate form in vertical cross-section with its sides converging downwardly, a smaller inner shell also of ovate form in vertical cross-section similarly arranged inside the outer shell at the top thereof and constituting a first-stage quiescence chamber a collecting dome or chamber,.

for the liquid of lower specific gravity, secured to the top side of said outer shell and centrally thereof, the top sides of said outer and inner shells being made to slope upwardly towards said dome to assist the flow of lighter liquid into said dome, an opening in said inner shell beneath the collecting dome by which the inner shell is in communication therewith, a bafiie around said opening to assist in directing the lighter liquid into the collecting dome and to prevent eddy currents from the main flow from disturbing the liquid in said dome, an inlet opening at one end of said inner shell, a vertical baffle plate adjacent the inlet and dividing off part of the inner shell to form a swirl chamber, an opening in the bottom of the inner shell, at the opposite end to the inlet, by which the inner shell is in communication with the outer shell, baiiie plates on both sides of said I therebetween into a number of lower quiescence chambers communicating with the collecting dome, baiile plates in said chambers to deflect the flow upwardly, an outlet opening at the bottom of said outer shell, and means for drawingofi the lighter separated liquid from the collecting dome.

'7. Apparatus for the separation of liquids of different-specific gravities comprising an outer shell of ovate form in vertical cross-section with its sides converging downwardly, a smaller inner shell also of ovate form in vertical cross-section similarly arranged inside theouter shell at the top thereof andconstituting a first-stage quiescence chamber, a collecting'dome or chamber, for the liquid of lower specific gravity, secured to the top side of said outer shell and centrally thereof, an opening in said inner shell beneath the collecting dome by which the inner shell is in communication therewith, an inlet opening at one end of said inner shell, a vertical bafile plate adjacent the inlet and dividing off part of the inner shell to form a swirl chamber, an opening in the bottom of the inner shell, at the opposite end to the inlet, by which the inner shell is in communication with the outer shell, division plates extending between the inner and outer shells and dividing the space therebetween into a number of lower quiescence chambers communicating with the collecting dome, an outlet opening at the bottom of said outer shell, and means for drawing as the lighter separated liquid from the collecting dome, comprising a draw-off alve operated by power mechanism under the at the top thereof and constituting a first-stage quiescence chamber, a collecting dome or chamber, for the liquid of lower specific gravity, secured to the top side of said outer shell and centrally thereof, an opening in said inner shell beneath the collecting dome by which the inner shell is in communication therewith, an inlet opening at one end of said inner shell, a vertical baffle plate adjacent the inlet and dividing off part of the inner shell to form a swirl chamber, an opening in the bottom of the inner shell, at the opposite end tothe inlet, by which the inner shell is in communication with the outer shell, division plates extending between the inner and outer shells and dividing the space therebetween into a number of lower quiescence chambers communicating with the collecting dome, an outlet opening at the bottom of said outer shell, a float within said collecting dome, levers connected to said float and secured to a shaft projecting through the side of said dome, an external control lever on the outer end of said shaft, a draw-oil valve by which the liquid collected in said dome is drawn oii, said valve being operated by a piston, coupled by its piston rod to the spindle of said valve, working within a cylinder under the control of a piston-valve, an operating rod connected tosaid piston-valve, and triggers on said rod engaged by said control lever whereby the piston-valve is moved to cause the main piston to open or close said draw-01f valve according to the position of the float within said dome.

9. Apparatus for the separation of liquids of different specific gravities according to claim 8, wherein the draw-off valve is maintained in 'or returned to, its closed position by a spring,

the power mechanism opening said valve against the action of said springs.

10. Apparatus for the separation of liquids of different specific gravities-comprising an outer shell of ovate form in vertical cross-section with its sides converging upwardly, a smaller inner shell also of ovate form in vertical cross-section similarly arranged inside the outer shell at the bottom thereof and constituting a first-stage quiescence chamber, a collecting dome or sump, for the liquid of higher specific gravity, secured to the bottom of said outer shell and centrally thereof and communicating therewith, an opening in said inner shell above the collecting dome by which the inner shell is in communication therewith, an inlet opening at one end of said inner shell, an opening in the top of the inner shell, at the opposite end to the inlet, by which the inner shell is in communication with the outer shell, division plates extending between the inner and outer shells and dividing the space therebetween into a number of quiescence chambers communicating with the sump, an outlet opening at the top of said outer shell, and means for running off the heavier separated liquid from the sump.

11. Apparatus for the separation of liquids of difierent specific gravity comprising an outer shell of ovate form in vertical cross section with its sides converging upwardly, a smaller inner shell also of ovate form in vertical cross section with its sides converging upwardly, formed at the bottom of said outer shell and constituting a first stage quiescence chamber, an inlet opening at one end of said inner shell, an opening in the top of said inner shell at the opposite end to the inlet, by which the inner shell is in communication with the outer shell, a curved baflle plate over said opening in the top of the inner shell, division plates attached to said inner and outer shells and extending into the space therebetweerr and dividing it into a number of additional quiescence chambers, an outlet opening at the top of said outer shell, an opening at the bottom of said inner shell, a flange surcock in said cover plate for draining off the heavier liquid collected in said sump.

12. Apparatus for the separation of liquids of different specific gravity comprising an outer shell of ovate form in vertical cross section with its sides converging upwardly, a smaller inner shell also of ovate form in vertical cross section with its sides converging upwardly, formed at the bottom of said outer shell and constituting a first stage quiescence chamber, said outer and inner shells being formed in two parts connected together by flanges formed thereon and bolted together, an inlet opening at one end of said inner shell, a bafiie placed adjacent said inlet, an opening in the top of said inner shell at the opposite end to the inlet, by which the inner shell is in communication with the outer shell, flanges on either side of said opening, a curved bafiie plate over said opening in the top of the inner shell, division plates attached to the outer face of said inner shell and alternating with division plates attached to the inner face of said outer shell, said division plates extending into thespace between the outer and inner shells and dividing it into a number of additional quiescence chambers, an outlet opening at the top of said outer shell, an opening at the bottom of said inner shell, a flange surrounding said'opening, an opening in said outer shell below said opening in the inner shell, a recess surrounding said opening in said outer shell, a cylindrical fitting extending below theopening in the outer shell and fitting into said recess and constituting a sump for the collection of the heavier separated liquid, a cover plate over the lower end of said fitting, a recess in said cover plate into which the lower end of said cylindrical fitting projects, packing washers in said recesses, screwed pillars extending from said outer shell through said cover plate, wing nuts on said pillars retaining said, cover in position and a drain cock in said cover plate for draining off the heavier liquid collected in said sump.

13. Apparatus for the separation of liquids of diflerent specific gravities comprising a housing ovate in transverse section, a partition extending longitudinally of the housing below the greatest horizontal cross-sectional area whereby to divide the housing into an upper intake portion and a lower outlet portion, a plurality of quiescence chambers in the upper portion througheach of which the mixture of liquids to be separated is passed in turn, a collecting chamber arranged above the quiescence chambers and communicating therewith, an inlet for said mixture in each quiescence chamber, and an outlet in the lower portion of the housing, said partition having an opening therethrough to permit the passage of liquid from the upper portion of the housing to the lower portion of the housing, said outlet being arranged forwardly of said opening.

14. Apparatus for the separation of liquids of diil'erent specific gravities comprising a housing ovate in transverse section with the narrowest portion lowermost, a partition extending across the housing below the widest portion thereof and extending longitudinally of the housing to divide the housing into an upper portion and a lower portion, a collecting chamber communicating with the upper portion, means for dividing the upper portion into a plurality of communicating quiescence chambers, an inlet for discharging the mixture of liquids into the upper portion adjacent one end of the housing, said partition having an opening therethrough adjacent the opposite end of the housing, said housing having an outlet in the lower portion adjacent the end opposite from said opening in said partition.

15. Apparatus for the separation of liquids 61' different specific gravities comprising an elongated housing ovate in transverse section with the narrowest portion lowermost, a partition extending across the housing and longitudinally thereof to divide the housing into an upper portion and a lower portion, a collecting chamber communieating with the upper portion, means for dividing the upper portion into a plurality of communicating end abutting quiescence chambers, an inlet for discharging the mixture of liquids into the upper portion adjacent one end 01' the housing, said partition having an opening therethrough adjacent the opposite end of the housing, said housing having an outlet in the lower portion adjacent the end opposite from said opening in said partition.

16. Apparatus for the separation of liquids of different specific gravities, comprising a plurality of quiescence chambers of ovate shape in vertical cross section, through each of which the mixture of liquids to be separated is passed in turn, an inlet for said mixture and outlets for 

